I am currently working on generating a dungeon in my mod. It contains some TileEntities which contents I want to randomize (MOB_SPAWNER, CHEST, and custom). For the MOB_SPAWNER I tried the following: 

TileEntity te = worldIn.getTileEntity(bd.getPos());

if(te == null){
	te = new TileEntityMobSpawner();
}

NBTTagCompound nbt = new NBTTagCompound();
NBTTagCompound spawn = new NBTTagCompound();
te.writeToNBT(nbt);
spawn.setString("id", "minecraft:zombie");
nbt.setTag("SpawnData", spawn);
te.readFromNBT(nbt);
						
worldIn.setTileEntity(bd.getPos(), te);

When I run this code, absolutely nothing appears to happen. The spawner looks the same and the spawner spawns Pigs.

 

Now my concrete question is: How would I properly change TileEntitiy values when doing WorldGeneration?

Making a dungeon mod -- someone after my own heart.

 

Well, for spawners I used this code:

 

	public static void placeSpawner(World world, int x, int y, int z, String mob) {
		// Place spawner block
		BlockPos pos = new BlockPos(x, y, z);
		if (MinecraftForge.TERRAIN_GEN_BUS.post(new DLDEvent.BeforePlaceSpawner(world, pos, mob))) return;
		if(isProtectedBlock(world, x, y, z)) return;
		if(!placeBlock(world, x, y, z, spawner)) return;
		TileEntityMobSpawner theSpawner = (TileEntityMobSpawner)world.getTileEntity(pos);
		
		// Set up spawner logic
		MobSpawnerBaseLogic logic = theSpawner.getSpawnerBaseLogic();		
		NBTTagCompound spawnData = new NBTTagCompound();
	    spawnData.setString("id", mob);
	    logic.setNextSpawnData(new WeightedSpawnerEntity(1, spawnData));
	}

 

Note that I never did manage to add custom attributes to the spawner / mob (I tried once, when I added them to items).  But for adding a mob, this works.

 

I have code for chests too, though it refers through several classes and methods to pick items.  The basic adding of items isn't hard though, if you want to see it.

 

For custom, you just have to add whatever attributes you have created.

Edited February 11, 20187 yr by JaredBGreat

That worked Excellently. Thank you!

Just let me know when your mods ready -- I'm always up for new dungeons to explore / fight through.